Conditionally acquire Giant in vm_contig_launder_page().

1 files changed, 4 insertions, 0 deletions

diff --git a/sys/vm/vm_contig.c b/sys/vm/vm_contig.c
index b26c46f..bd9233b 100644
--- a/sys/vm/vm_contig.c
+++ b/sys/vm/vm_contig.c
@@ -66,6 +66,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/systm.h>
 #include <sys/lock.h>
 #include <sys/malloc.h>
+#include <sys/mount.h>
 #include <sys/mutex.h>
 #include <sys/proc.h>
 #include <sys/kernel.h>
@@ -92,6 +93,7 @@ vm_contig_launder_page(vm_page_t m)
 	vm_page_t m_tmp;
 	struct vnode *vp;
 	struct mount *mp;
+	int vfslocked;
 
 	object = m->object;
 	if (!VM_OBJECT_TRYLOCK(object))
@@ -115,11 +117,13 @@ vm_contig_launder_page(vm_page_t m)
 			vm_object_reference_locked(object);
 			VM_OBJECT_UNLOCK(object);
 			(void) vn_start_write(vp, &mp, V_WAIT);
+			vfslocked = VFS_LOCK_GIANT(vp->v_mount);
 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread);
 			VM_OBJECT_LOCK(object);
 			vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
 			VM_OBJECT_UNLOCK(object);
 			VOP_UNLOCK(vp, 0, curthread);
+			VFS_UNLOCK_GIANT(vfslocked);
 			vm_object_deallocate(object);
 			vn_finished_write(mp);
 			vm_page_lock_queues();